The induced pluripotent stem (iPS) cell field has been red hot over the approximately first half dozen years of its existence from 2006-2011.

However, as I blogged about here part way through 2012, it was showing signs of cooling off a bit in terms of the shear output of publications.

It turns out that now that the year 2012 is basically in the history books from a publications standpoint (there might be a few stray pubs from 2012 still to be added to databases, but not many), there were fewer iPS cell pubs in 2012 than in 2011 (555 vs 565, respectively). This is based on a Web of Science search as follows: Title=(ipS cell OR iPS cells OR induced pluripotent stem cell OR induced pluripotent stem cells OR induced pluripotency OR induction pluripotent).

This is the first year-over-year decrease for the iPS cell field.

Also, the number of citations barely increased in 2012, reflecting a dramatic change from the almost exponential increase in papers citing iPS cell papers in the preceding years.

This trend overall is not necessarily a bad thing, but rather showing a sign that the field is maturing.

The first month of 2013 has also been surprisingly slow for iPS cell papers: just 22 so far. While today is January 31, I realize there may be more pubs in the month of January showing up. Still, it suggests the cooling off trend may continue. Again, I don’t see that as a bad thing. There are so many iPS cell papers now that no one can read them all and probably a significant fraction are not that important.